import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class code1_2 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.next();
        StringBuffer strs = new StringBuffer(str);
        for(int i=strs.length()-3;i>0;i-=3){
            strs.insert(i,",");
        }
        System.out.print(strs);
    }
}